A special CRC subtype characterized by a high tumor mutational burden (TMB), more tumor neoantigens, and a higher density of tumor infiltrating lymphocytes.
These immunogenic features make dMMR CRC highly responsive to treatment with PD-1 blockade.
dMMR CRC is not benefited by neoadjuvant chemotherapy.
PD-1 blockade of dMMR CRC is highly effective with objective response rates in all patients, and 60% achieving pathologic complete response.
100% of patients with localized dMMR rectal cancer achieves a complete remission after six months of treatment PD-1 blockade.
Results of neoadjuvant immunotherapy for localized dMMR CRC show high rates of major and complete pathological response (Emilojou O).